Urinary tract infection (UTI) affects approximately 3% of all women aged 45 to 65 years each year. Although single infections are generally self- limiting and easy to treat, some women suffer from chronic recurring infections. The impact of recurring infections on quality of life can be substantial, resulting in repeated physician visits and disability days. Despite the increasing prevalence of bacteriuria and symptomatic UTI with age, no studies have examined the role of health behaviors or bacterial virulence factors on risk of UTI among older women. Hormonal changes with aging and associated impact on the vaginal flora and peri-urethral environment may explain at least part of the increased risk of UTI with age. There has been some suggestion that supplemental estrogen may increase risk of UTI through conversion of vaginal flora to premenopausal ecology, although others suggest that supplemental estrogen may decrease risk by increasing resistance of urogenital epithelia. It is the overall goal of this study to examine how menopause and associated use of supplemental estrogen modifies the relationships between health behavior, bacterial virulence factors and risk of UTI among White and Non-White women aged 40 to 65. Aim 1. Describe the associations between health behavior, medical history, menopausal status (pre-, per- or postmenopausal), estrogen use and urinary tract infection among White and Non-White women by comparing the frequency of these characteristics among 1600 women aged 40 to 65 with (n=400) and without (n=1200) physician-diagnosed, culture confirmed symptomatic UTI. Aim 2. Describe the associations of health behavior, medical history, menopausal state and estrogen replacement therapy with UTI by racial/ethnic group. Aim 3. Compare the bacterial virulence characteristics of uropathogens causing symptomatic UTI with those of uropathogens causing asymptomatic bacteriuria among controls. UTI has a significant impact upon many women's lives. The role of health behavior, menopause, estrogen replacement therapy, and bacterial virulence factors on UTI risk among 40 to 65 year olds is only beginning to be explored. If the proposed study identifies risk factors which, if modified, could prevent even a small proportion of the 823,000 UTI that occur annually in this age group, this study will have made a significant contribution to women's health.